Daryl Hannah's *ss in splash was the first movie nudity i saw as a kid, it was PG too, but no titties. I don't think my unspoiled mind could have handled *ss and titties in one scene. Nowadays kids are probably up to gaping-ass porn by age 7.

The Andromeda Strain, 1971, Rated G. Dead young woman's lovely titties on screen for more than several seconds. (Movie dead, so live actress of course.) I guess that could be the next site of this fad.